HEAD OF LAKE WAKATIPU
Kei aku rangatira tēnā rā koutou. Nau mai ki tēnei kawerongo. At ORC, the Covid-19 red alert level means most of our staff are working from home, except for some key workers who are out of the field to keep our communities safe.
Regardless, we are keeping an eye out for weather changes and flood risks as usual. Our responsiveness to heavy rainfall events will not be affected, so we can alert the community at the Head of the Lake area in a timely manner if necessary.
The ORC flood response team were kept busy a few weeks ago – working with Metservice to discuss weather forecasts and warnings, and monitoring of rainfalls, river flows and lake levels throughout the weather event.
While the main focus of the weather system was further north of Otago and especially along the West Coast, there was still significant rainfall in the headwaters of the Lake Wakatipu and Lake Wanaka catchments – one of our rain gauges in the Makarora area recorded a very high 24-hour rainfall total of 380mm!
During this event, the Dart River peaked at a flow of about 1,070 cumecs, and water levels at Lake Wakatipu and the Glenorchy lagoon rose by around 0.5-0.55 metres.
The ORC Environmental Monitoring team were in the Dart-Rees area last week to carry out helicopter-based flow measurements while the rivers were at higher flows. These are used for calibration of the flow estimates at the river flow monitoring stations. You can see how it works in this video.
The photos below were taken on 3 February by the ORC Environmental Monitoring team, showing the Dart River at moderate flows of about 400-450 cumecs.
